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prkaye

Well Known Member
For painting, I've heard of people linking two or more small compressors in parallel to get the required cfm.
I was told that I would need 13cfm (for Stewart Systems paint). My question is, is this 13cfm at the gun pressure of 23psi, or is it 13cfm at the tank pressure of 100psi? Big difference there... my current compressor is rated 7.2cfm @ 40psi and 5.4 cfm @ 90psi. Would two of these compressors be suitable for painting?
 
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Typically measured at the gun...

...and don't forget the electrical power requirements. Depending on the power required, you may need two separate ac power sources and not two power outlets on the same circuit.
 
I rigged two of them together to paint my -10...I saved major money doing it myself, enough money to justify buying a nice big powerful compressor if I had it to do all over again. A good supply of air with adequate volumn and pressure clear of moisture and oil is PRICELESS when doing paint. I own a turbine system but wasn't super happy with it so I just used my HVLP rig on two compressors. It worked OK but I would buy an adequate compressor, you won't be sorry.
 
Rivethead said:
...I'm going to predict that a jury rigged system is going to shoot well for about 30 seconds before it begins to drop off to a point that you'll begin to start noticing a change...
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It would take a VERY jury rigged system (no or POS regulator) to get that result. Yes, the tank pressure will begin to fall immediately, but a decent regulator should hold the line pressure steady. You'll know whether your compressor(s) is (are) adequate by noting whether or not it (they) can maintain the tank(s) above the reg setpoint.
 
cutting canopy

The pneumatic cutter uses so much air that I could only cut 6" to 1' of canopy before I had to wait for a recharge. I borrowed a second compressor and with a T fitting I was able to quickly able to put them on the same supply line. WOW what a difference, I hardly had to slow down at all. Remember, each compressor on its own circuit.

Steve Barnes, The Builders Coach
 
It definitely works!

I did this and I've painted about a dozen cars and one airplane.

If you have a good regulator at the gun, NOT an $8 Harbor Freight regulator, a big enough tank 60++, and you work in short segments like most jobs require, you're smaller compressor may carry the load. If not, just flip on # 2. The key is a good regulator at the gun.

Equally important, the only worse than an engine that quits in flight is a compressor that dies in the middle of a shoot. With two compressors, you've got a safety net and the job may go more slowly, but at least you can complete it.

I ONLY work with an HVLP gun.
 
Just recently painted a BIG wing that way. Works very well, with no pressure drops at all. Just a lot of noise from those two buggers humming away.

We're blessed with 240 volts here, so I could easily run both compressors plus all my lighting off one 16 Amp circuit.

Hans

(Ever tried running a media blasting cabinet on just one small compressor? Talk about frustrating!)
 
Instead of 2x 20 gal compressors, why don't you buy a used 60 gal compressor
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Power and space constraints mainly. I have no need for a compressor that large other than for painting. I also don't have a 240V circuit in my shop or my hangar, and don't want that monstrosity taking up space in my garage after the project is done.

I'm leaning heavily towards a turbine with an extra hose for cooling. Busy bee in ottawa has the 4-stage mini-mite regularly 975, on sale for 769. If this works, would be MUCH more convenient that plumbing together compressors and all the required filters and water separators, which together would cost almost as much as the turbine. This little turbine is very portable. My only fear is investing that much money in it and then discovering I can't get a good finish with it...
 
Stewart Systems

Phil,
I talked to a gentleman last year who had painted his RV6A (which was RV of the week in (7) 2005) with SS paint. He used the recommended gun (DeVilbiss Finish Line III) and a 2 HP 30 Gal compressor. After 2 years (mostly hangared) it was holding up well and he reported that fuel spills did not bother it.
I am planning on painting my 7A with SS and have a IR 60 gal single stage 3HP compressor. If all I had was a 30 gal compressor, I would try it and if it didn't work, maybe look at the turbo unit then, or adding another (borrowed or rented) compressor.
Not first hand, but hope this helps.
 
Two compressors in parallel

If you just connect two compressors in parallel, the first one to start when its pressure switch closes will begin pumping up the pressure and will prevent the second compressor's pressure switch from closing unless the first compresor can't keep up with demand. In that case, the pressure will continue to decrease until the second compressor starts, and the pair of them begin working together.

If that's what you want, you should adjust the two pressure switches so they don't start simultaneously, or the combined starting current could be a problem for your electrical circuit.
 
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